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Title: Pressure driven spin crossover and isostructural phase transition in LaFeO{sub 3}

We have studied the behavior of LaFeO{sub 3} under pressure (P) using density functional theory (DFT) and atomistic simulations. Ground state structural properties of LaFeO{sub 3} are correctly described by atomistic simulations. The effect of high pressure shows that there is an isotropic compression up to 100 GPa. However, DFT calculations show that within pressure range 0 < P < 32.4 GPa, LaFeO{sub 3} retains its ground state electronic structure. On the other hand, at P ∼32.4 GPa high to low spin magnetic phase transition is observed, which is accompanied by 6.9% volume collapse of LaFeO{sub 3} unit cell, while retaining the ground state orthorhombic crystal structure, i.e., isostructural phase transition. Furthermore, the band gap is closed leading insulator to metal transition. This differing behavior observed by the two techniques can be attributed to the omission of magnetic effects in static simulations. The simultaneous magnetic, electrical, and structural (volume collapse) phase transitions of LaFeO{sub 3} under compression as revealed by DFT calculations corroborate experimental findings. From these results, we can elaborate the mechanism of phase transition in LaFeO{sub 3}: increasing crystal field induces a high spin to low spin transition, which in turn drives the electrical transitions and volume collapse.
Authors:
 [1] ;  [2] ; ;  [1] ;  [1] ;  [2] ;  [3] ;  [4]
  1. EMMG, Physics Division, PINSTECH, P.O. Nilore, Islamabad (Pakistan)
  2. (Pakistan)
  3. Theoretical Physics Division, PINSTECH, P.O. Nilore, Islamabad (Pakistan)
  4. Department of Physics, University of Malakand, Chakdara (Pakistan)
Publication Date:
OSTI Identifier:
22267763
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 114; Journal Issue: 24; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; COMPRESSION; CRYSTAL FIELD; DENSITY FUNCTIONAL METHOD; ELECTRONIC STRUCTURE; GROUND STATES; METALS; ORTHORHOMBIC LATTICES; PHASE TRANSFORMATIONS; SIMULATION; SPIN